1. Field of the Invention
The invention relates to a device for treating human extremities by means of intermittent compression of the type comprising at least one sleeve for application on the bodily parts in question, having flexible chambers arranged one after another in series which may be successively inflated and then deflated under automatic control, having a number of valves corresponding to the number of chambers, each of which one is associated with chamber and by means of which the inflation and deflation of the chambers is controllable, as well as a feed pipe supplied from a compressed air source via a control system, whereby the chambers may be supplied with compressed air via the valves.
2. Description of the Prior Art
A device of this type has been described in the German published Patent specification No. 25 01 876. In this device, the separate inflatable chambers are directly interconnected by means of valves, the valves furthermore each being connected to short branch pipes which are in turn supplied by a common feed pipe supplied from a compressor. The individual valves which are thus connected in parallel, and are all supplied with compressed air at the same time for inflation of the chambers, operate one after another however, so that at first only the distal chamber is inflated. After its maximum pressure is reached, the valve of the distal chamber is switched over which couples it to the next chamber in the proximal direction, so that the next proximally following chamber is then inflated through the branch pipe just referred to, whilst the distal chamber is vented to the open air or into a return pipe. These operations are repeated from one chamber to another. Whilst the chamber which is next in each case is thus being filled, the chamber preceding it is vented at the same time, so that a peristaltic or undulant pressure is applied to the patient's limb by means of the inflating and deflating chambers.
A disadvantage of this device consists in that the period during which each chamber becomes and stays inflated is substantially uncontrollable. A rapid inflation of the chambers on the one hand and a comparatively protracted persistence of the inflated state of the chambers on the other hand, are thus impossible. Even the venting stages are no longer variable once a valve has been assembled and installed except by a change of the volumetric flow of the inflating compressed air, so that it is impossible to undertake a treatment best suited to the current state of the patient's complaint. Furthermore, the valves are of very complex structure and therefore difficult to manufacture, so that the valves can be produced only at a very high investment cost.